Control for friction clutches



Jan. 29, 1 946.

R. STEVENSQN CONTROL FOR FRICTION GLUTQHES Filed March 50, 1942 5 Sheets-Sheet 1 I 56' i/ 3 W IN V EN TOR.

fioza/i- 192 42 1 6/2300 A TTORNEYS.

Jan. 29, 1946. R, STEV SON 2,393,835

CONTROL FOR FRICTION CLUTCHES 3 Sheets-Sheet 2 Filed March 30 1942 INVENTOR. .Qaerf Jf VIP/7.90M

ATTORNEYS.

Jan. 29., 1946.

CONTROE FOR FRICTION CLUTCHES R. STEVENSON 2,393,:835

Filed March 30, 1942 3 Sheets-Sheet 3 A TTORNEYS.

Patented Jan. 29, 1946 CONTROL FOR FRICTION CLUTCHI BS Robert Stevenson, Providence, R. 1., asslgnor to Stevenson Engineering Corporation, a corporation of Rhode Island Application March 30, 1942, Serial No. 436,781

1 Claim.

This invention relates to a friction clutch and more particularly to a hydraulic control for the clutch.

Heretoiore in the use of friction clutches some dililculty has been experienced in the control of the clutch in that the take-up for applying pressure on the friction surfaces has been too rapid, which has been the experience of lever controls for such friction clutches.

One of the objects of this invention is to provide a hydraulic control for the friction clutch whereby the pressure may be more accurately controlled, such as through a needle valve or the like, that a very slow take-up may occur.

Another object of the invention is to provide an arrangement of hydraulic-take-up for the clutch by which-a large amount of pressure may be applied to the friction surfaces.

A further object of the invention is to provide a seal for the hydraulically applied pressure whereby the pressure of the liquid itself will act upon the seal to control the pressure applied to the seal.

With these and other objects in view, the invention consists of certain novel features of construction, as will be more fully described and particularly pointed out in the appended claim.

In the accompanying drawings:

Fig. l is a sectional view of the operating parts of my clutch showing the conventional mounting I for the shaft to which power is applied;

Fig. 2 is a view similar to Fi l on an enlarged scale showing the friction plates and the fluid transmission thereto;

Figs, 3, 4, 5, 6 and 7 are sections respectively ,on correspondingly marked lines of 2; and

Fig. 8 is a sectional view of a modified arrangement showing a double clutch to which the invention is applied.

This invention consists generally in the use of a fixed ringlike member which presents sealing surfaces on its opposite sides to be engaged by a rotary part of the clutch and the provision of a shaft within this rotary part which will be coupled or uncoupled to the rotary part through friction surfaces, fluid being caused to enter through the fixed part and being transmitted through one or both, or between the rotary parts to apply pressure on the friction surfaces with a sleeve being utilized for the sealing of the entrance of this liquid which will be carried by the outer rotary part, and the following is a more detailed description.

With reference to the drawings, 9 designates some suitable supporting base with mounting standards I0 and H for rotatably supporting a shaft l2 by ball bearings l3 which shaft is suitably driven in any desired manner not here illustrated, it being understood that'this shaft will becontinuously rotated and from this rotation there will be taken oif intermittently driving power as desired. A support I4 is provided with a ball bearing l5 for suitably rotatably mounting the member I6 which carries a gear I! from which the power to be derived intermittently is taken, said gear being keyed as at It to this member IS. A bushing I9 is provided at one end of this member it which engages the shaft l2. Collars 20, 2| and 22 are utilized for engagement with the supports III, II and M to suitably hold the ball bearings in place while another collar 23 is provided for the inner race of ball bearing I5.

The shaft H has keyed to it a plurality of plates 25 such for instance as by means of keys 26 (see Figs. 2 and 4). These plates 25 are slidable upon the shaft 52 axially thereof along the keys 2%. Therotary part i 6 is provided with a cup-shaped housing 21 which has keyed to it a plurality of plates 28 by means of keys 29 (see Fig. 3) located in recesses 30 in this housing.

.The plates 28 alternate with plates 25 and extend between them. These plates 28 are likewise slidable-with reference to the housing 2'! axially of the apparatus.

In order to cause the member it to be rotated with the shaft 52 which is continuously driven, pressure is applied to these plates 25 and 28 causing t em to move together with suficien't friction so that drive will be imparted from the shaft E2 to the member it. For this purpose I have provided pressure means (see Fig. 2), the details of mounting of which consists of a tubular member 3i which telescopes over the shaft I it and is provided with a head, 32, abutting shoulder 33 on shaft it, to limit its axial movement in one direction while it is keyed to the shaft by the same Woodruff keys 2% which lock the plates 25 to the shaft. This head also serves as an abutment against which the end of the series of plates engages, there being illustrated a plate 28 in engagement with the right hand surface of this head, as shown in Fig. 2. The tubular member is recessed as at 35 for the transmission of fluid axially of the shaft and between the shaft and the tubular member.

A cylinder designated generally 36 (Fig. 1) consists of an outer wall 31 (see Fig. 2) fixed to the flange 38 of a collar 39 which flange forms a bottom wall of the cylinder while this collar 39 is The end 45 of keyedtothetube 3| bythepinsllsoastobe locked therewith. A second collar 4| has its'surface 42 providing the inner-wall of the cylinder 38 while within this cylinder there is located the 35 is annular and thus is always in communicasimilar conduits of points of tion with these conduits or which there ar; four located at spaced 90 about this member- A ring 58 encircles the shaft and tubular member 3| and is fixed with relation thereto, having a conduit 5| entering this ring and held by some suitable bracket 52 against rotation. Conduit 53 extending radially of the ring communicates with the annular space 54 in the ring about the tubular member 3| while openings 55 (see Fig. 7) through the member 3I serve to communicate with the annular space 35 between the member 3| and the shaft I2. Thus, fluid may enter through the tube 5 I, conduit 53, annular space 54, holes 55, to the annular space 35 and be transmitted to the piston so as to force the same to press the plates 25 and 28 into the desired frictional engagement. When the pressure is released in order to draw the piston away from the plates, I have provided pins 58 secured in the bottom wall 38 in any suitable manner, each of which has a head 51 with a spring 58 to engage a suitable abutment 58 threaded into an enlarged bore in the piston so as to push the piston to the the area 14 the pressure will tend to force'the sleeve 81 toward the sealing ring proportional to the differential of the pressures on the surfaces against which it acts, and accordingly pressure 1 will be applied to the sealing surfaces on one side of the ring and transmitted through the ring, so that pressure will be similarly applied to the sealing surface on the opposite side of the ring,

and an effective seal will be provided between the ring 58 and the rotating parts of my clutch.

In the modification illustrated in Fig. 8 the shaft is designated I2 as previously, mounted in roller bearings 88 at one end and a ball bearing 8i at the opposite end. The enlarged portion 82 of this shaft has mounted thereon a ball bearing 83 to support one part 84 which is to be intemiittently driven while another part 85 which is to :be intermittently driven is supported through a bushing bearing 86. Clutch plates 28 are keyed to the parts 84 and 85 as described heretofore. .In this case however the tubular member or follower 81 while it rotates with the shaft I2 has longitudinal movement relative to the shaft and is provided with a head 88 screwed onto the shaft as at 88 provided with a central abutment member 88. On either side of this central abutment member there are provided a plurality of plates 25 keyed to this head 88 in the same manner as the plates 25 are keyed to the tubular member 3| and shaft I2, for instance as by Woodruff keys 28.

right, as shown in Fig. 2, there being a suflicient clearance 88 for movement of the piston in this direction.

A collar BI is locked to the tube 3| by means of the set screws 82 and is located on the opposite side of the fixed ring 58. The opposite surfaces of the fixed ring 58 as at 83-and 64 are provided with a ground area for sealing purposes, the collar Bl being provided with a flange 65, and sealing surface 68 to engage with this surface of the fixed ring on one side, while a sleeve 61 is slidably mounted upon the collar 38 with piston rings 68. engaging the inner surface thereof, also having a flange 68 with a ground surface 18 to engage the ground surface 63 on the opposite side of the ring. Springs 1| force this sleeve to cause the surface 18 to engage the sealing surface 83 to transmit pressure to the ring to cause sealing engagement between the surfaces 84 and 66. This spring however applies only a small amount of pressure in the system. However the pressure n the sealing surfaces isv controlled by the inwardly extending portion 12 of the sleeve which presents a surface 13 on one side of a greater extent than the surface 14 on the other side between the flange 68 and the tubular member 3|. A certain amount of seepage of the fluid will occur along the outer surface of the member 3| so that the area 15may be filled 'with fluid which will be transmitted through small openings 16 to the area within the flange 68 and thus there will be present in this fluid the same pressure as applied through the conduit 5|. As the area 13 is greater than provided with flanges The tube 81 is recessed to provide a space 82 extendingannularly about the shaft I2 between the member'81 and the shaft I2. In this case a cylinder 83 encircles th shaft and tubular member 81, having a cylindrical wall 84 and end walls 85 and 88. A piston 81 is located in this cylinder with piston rings 88 engaging the walls thereof. while providing chambers 88 on one side and I88 on the other side of this piston in this cylinder. The piston is provided with a guide pin I8I extending through the same with the coil springs I82 and I83 on either side which are in balanced relation to keep the piston central of the cylinder when no other force is exerted thereon. This piston is locked to the tube 81 or formed as an integral part thereof.

In order to force the piston 81 in different directions I apply fluid to the chambers 88 or I88. A non rotary ring I84 is provided about a tube on one side of the cylinder and a non rotary ring I85 is provided about the tube on the other side of the cylinder. These rings each have an annular space I88 and I81 to which fluid is fed through tubes I88 and I88. The fluid is fed from this annular space I86 through conduit 8 to the chamber 88 to force the piston in one direction (to the right, Fig. 8), or is fed from the space I81 through the conduit III into the space |88 to force the piston in the opposite direction. When this piston is forced to the left as shown in Fig. 8 the plates will cause a drive of the member 84, whereas if this piston is forced to the right ber 85.

In order to provide a seal about the rings I84,

I85 flanges H2, 3' are provided on the opposite sides of the cylinder 83 which are ground and engage ground .mating surfaces H4, H5 on the rings I84 and I85, while on the other side of the rings there are provided sleeves H8 and III, also 8 and 8 each with engage mating ground surwhen forced thereagainst. serve to force these sleeves ground surfaces to faces onthe ring Springs I28 and |2I and which will be present just inside th flange II 8 will assist in forcing the sleeve to cause the sealing surfaces to engage. 1 This action is the same as heretofore presented only it is provided in duplicate with the surfaces of the two sleeves acting toward each other to bring all of the parts into firm sealing engagement. Piston rings I 26 and I2! serve to seal the sliding engagement of the sleeves on the tube I21 on which these parts I are mounted.

I claim:

In a fluid actuated mechanismhaving a solid 7 shaft and a surrounding tubular member rotatable therewith and'a passageway formed therebetween for transmitting fluid to said mechanism, means for transmitting fluid to said passageway comprising a fixed ring embracing said tubular member and provided with an annular recess, said ring being connected to a fluid supply source, a port extending through said ring to said recess, ports connecting said recess and said passageway and a seal sleeve surrounding said tubular member and slidable therealong and having a radially extending flange provided with unbalanced areas exposed onopposite sides to the pressure of the actuating fluid whereby said seal sleeve will be moved in directions dependent on the respective areas on the different sides of the flange.

ROBERT STEVENSON. 

